Field archaeologist Andrew Bastier shook dirt through a screen, leaving behind stones and a fragment of volcanic glass.

With volcanic glass not found naturally in the Rogue Valley, whoever used the material in the distant past had to have obtained it from east of the Cascade Range.

"When you see that, you know obviously it was traded or traveled to get here," Bastier said, dropping the fragment into a container for safekeeping. "It's razor sharp, too."

Almost hidden in a square hole in the ground, Ashland-based Cascade Research Field Foreman Greg Applen continued to fill buckets of earth and lift them out for Bastier to screen.

The researchers are hunting for American Indian artifacts at the future site of Ashland Creek Park near the intersection of East Hersey Street and Water Street. The park land borders Ashland Creek.

The State Historic Preservation Office has required the Ashland Parks and Recreation Department to have more excavation done after initial test pits dug by Cascade Research in April uncovered fragments of American Indian artifacts.

The initial testing was prompted by the fact that no previous archaeological surveys have been completed on the park land, according to the state.

So far, Cascade Research has mainly discovered flakes from the creation of stone tools, said company owner and principal investigator Dennis Gray.

A core was also discovered, he said.

"A core is the remains of a stone that was worked to take off flakes to make tools," Gray said.

It's too early to tell what American Indian tribe or tribes used the site, he said.

Upstream near Ashland Creek, archaeologist Jeff LaLande identified scrapers, obsidian flakes, hammer stones and other artifacts that substantiated the past existence of a Shasta Indian village in the area of the downtown Plaza.

The Plaza underwent a reconstruction that wrapped up in the spring of 2013. LaLande was tasked with searching for artifacts before the Plaza was resurfaced with pavers.

He and his team also discovered assorted American Indian artifacts beneath the Calle Guajauato pedestrian walkway behind Plaza businesses. A project to install new water and electric lines beneath the walkway and add new pavers was completed this spring.

Gray said there's no way of knowing yet what finds may be underground at the Ashland Creek Park site.

"We've found no substantial tools yet, but we're just getting into it," he said.

Artifacts uncovered there will determine how long the archaeological work will continue, Gray said.

The Parks Department hopes to begin development of the park in late June, said Parks Superintendent Bruce Dickens.

The first phase will include a natural meadow along the creek, walking paths, a playground, a restroom and the relocation and enlargement of a community garden already on the land, he said.

The $619,900 cost of phase one will be partially funded by a $309,950 grant from the Oregon Parks and Recreation Department. The Ashland Parks and Recreation Department will provide matching funding.

Costs for the second phase, which will include a half-court basketball court and a shelter, haven't been estimated or budgeted yet, Dickens said.

Staff reporter Vickie Aldous can be reached at 541-776-4486 or valdous@mailtribune.com. Follow her at www.twitter.com/VickieAldous.